This library implements a Websocket server running on an ESP2866 Board e.g NodeMCU. It's based on the proposed standard published December 2011 which is supported in the current versions (June 2012) of Firefox, Chrome, and Safari 6.0 beta (not older Safari, unfortunately) and thus is quite usable.
The implementation in this library has (still) some restrictions:
- The server only handles TXT frames.
- The server only handles single byte chars.
- The server only accepts final frames with maximum payload length of 64 bytes. No fragmented data, in other words.
- For now, the server silently ignores all frames except TXT and CLOSE.
- The amount of simultaneous connections may be limited by RAM or hardware.
- There's no keep-alive logic implemented.
Required headers (example):
GET /whatever HTTP/1.1
Host: server.example.com
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
Sec-WebSocket-Version: 13
The server checks that all of these headers are present, but only cares that the version is 13.
Response example:
HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
The last line is the Base64 encoded SHA-1 hash of the key with a concatenated GUID, as specified by the standard.
Daniel O'Neill: Compared to the original, this library consumes significantly less RAM and provides additional functionality.
- Arduino IDE 1.6.5 or greater
- esp2866 for Arduino IDE 1.6.5-947-g39819f0 or later
- An ESP2866 Board e.g NodeMCU 0.9 or 1.0
- A Websocket client that conforms to version 13 of the protocol
Install the library to "libraries" folder in your Arduino sketchbook folder. For example, on a mac that's ~/Documents/Arduino/libraries.
Try the supplied echo example together with the the web based test client to ensure that things work.
Start playing with your own code and enjoy!
Don't forget to place a big fat disclaimer in the README. There is most certainly bugs in the code and I may well have misunderstood some things in the specification which I have only skimmed through and not slept with. So please do not use this code in appliancies where living things could get hurt, like space shuttles, dog tread mills and Large Hadron Colliders.